[Mesa-dev] [PATCH] nir: fix block iterator to not forget fxn->end_block

[Rob Clark]

From: Rob Clark <robclark at freedesktop.org>

With the switch to new block iterator macro, we silently stopped
iterating over the end-block.  Which caused nir_index_blocks() to not
index the end-block.  Resulting in funny looking nir_print's like:

impl main {
	block block_0:
	/* preds: */
	intrinsic copy_var () (gl_FragColor at out-temp, gl_Color) ()
	intrinsic copy_var () (gl_FragColor, gl_FragColor at out-temp) ()
	/* succs: block_0 */
	block block_0:
}

I don't *think* there are any more serious consequences of not iterating
the end_block, but it's probably also a good idea to not subtly change
behavior compared to the old fxn-callback based iterator.

Signed-off-by: Rob Clark <robclark at freedesktop.org>
---
 src/compiler/nir/nir.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/src/compiler/nir/nir.c b/src/compiler/nir/nir.c
index 867a43c..1f51b31 100644
--- a/src/compiler/nir/nir.c
+++ b/src/compiler/nir/nir.c
@@ -1512,12 +1512,18 @@ nir_block_cf_tree_next(nir_block *block)
       return NULL;
    }
 
-   nir_cf_node *cf_next = nir_cf_node_next(&block->cf_node);
+   nir_cf_node *parent = block->cf_node.parent;
+   nir_cf_node *cf_next;
+
+   if ((parent->type == nir_cf_node_function) &&
+       (block == nir_cf_node_as_function(parent)->end_block))
+      cf_next = NULL;
+   else
+      cf_next = nir_cf_node_next(&block->cf_node);
+
    if (cf_next)
       return nir_cf_node_cf_tree_first(cf_next);
 
-   nir_cf_node *parent = block->cf_node.parent;
-
    switch (parent->type) {
    case nir_cf_node_if: {
       /* Are we at the end of the if? Go to the beginning of the else */
@@ -1532,9 +1538,12 @@ nir_block_cf_tree_next(nir_block *block)
    case nir_cf_node_loop:
       return nir_cf_node_as_block(nir_cf_node_next(parent));
 
-   case nir_cf_node_function:
+   case nir_cf_node_function: {
+      nir_function_impl *func = nir_cf_node_as_function(parent);
+      if (func->end_block != block)
+         return func->end_block;
       return NULL;
-
+   }
    default:
       unreachable("unknown cf node type");
    }
-- 
2.5.5